Here's a quick tutorial to get back into the swing of things for 2013. I was asked about drawing coastlines. This is just a technique question so it's software agnostic.

1. Starting point

Here's the basic shape of the coastline - this is what I see a lot in turnover sketches at the early design stage. It's very blobby and indistinct, and looks nothing like a real coastline. The key is the regularity and smoothness of the line

2. Break it up!

I've followed the general shape of the coastline, but broken the line into a more jagged pattern. Some regions are almost sawtoothed. Try not to make features and variations the same size. Coastlines are fractal - they should look similarly broken up at a range of different zoom levels. Add some smooth coves for beaches to give variety (like the beach under the 2.)

Add islands along the coast. I tend to add them off peninsulas - where a spur of rock stretches out into the sea and leaves a trail of islands pointing out - or in inlets where the islands can mimic the shape of the negative space.

3. Edge detail

At this stage I've added a range of marks to the land to indicate the structure of the coastline and hint at hills, valleys, and the form of that beach I mentioned earlier. A lot of coastline has a sharp drop to the sea, and these lines hint at that structure.

A nice little guide to hand-drawn coastlines. The point about smooth areas for beaches is a particularly easy one to forget. There are some amazingly straight and smooth coastlines in reality that I find are often overlooked features in fictional maps.